Final answer:
Materials stacked on a roof must be stable to prevent them from posing a hazard to workers on the roof and to individuals and property below. It is crucial for safety to ensure that stacked materials near the edge of a roof do not slide, shift, or topple over.
Step-by-step explanation:
When working on a roof, it is imperative to prioritize safety measures to prevent accidents. Materials that are piled, grouped or stacked near the edge of the roof must be stable to prevent them from becoming hazards. Stability is crucial not only for the safety of the workers on the roof but also to protect individuals and property on the ground. To achieve stability, the materials should be stacked in such a manner that they are not prone to sliding, shifting, or toppling over. Moreover, workers should be careful not to drop objects from a height, maintain a safe distance from the edge, and be cautious about where the objects might fall, ensuring they do not cause damage or pose a danger to people or vehicles passing below.